A Malaria Outbreak in Ameya Woreda, South-West Shoa, Oromia, Ethiopia, 2012: Weaknesses in Disease Control, Important Risk Factors

Malaria is endemic in Ethiopia but regional health bureaus have set goals for elimination of the disease through the implementation of aggressive malaria control and eradication measures. In May 2012 an increased number of malaria cases were reported from Ameyaworeda, South-West Shoa, Ethiopia, which previously had been targeted for elimination. We investigated to understand associated risk factors and propose control measures.We reviewed data from health post records from 2008 to 2012 to identify the baseline incidence of malaria for Ameya. We defined a confirmed case as a patient with malaria confirmed by microscopy or a rapid diagnostic test. From May 18 to June 10, 2012 we randomly selected 144 newly diagnosed malaria patients and compared with 144 community matched controls. Multivariate analysis was performed using Epi Info version 3.5.3. We also assessed environmental conditions.The baseline incidence rate for malaria prior to the outbreak was 1/1000 population. Between March 2012 and May 2012 4768 cases were reported with a peak during May [Incidence: 37per 1,000 and no fatalities]. Using multivariate analysis, cases were found to be less likely to use ITN’s [OR: 0.09; 95%CI 0.05-0.16] and less likely to spray their houses [OR: 0.45; 95%CI 0.21-0.97] when compared with controls. Environmental assessment revealed the presence of stagnant water, which was favorable for mosquito breeding. We identified several factors that contributed to the outbreak, which included a low utilization of ITN’s, ideal conditions for vector breeding, a weak case detection system. We recommended and helped implement a community awareness program on the utilization of ITN’s, environmental management and focal indoor residual spray (IRS).